Came across this site which is a resource put up that cross references records held by the Imperial War Museum and the Commonwealth War Graves Commission. You can search by location or postcode and it will overlay WWI service personnel on a map down to street level with their home address at the time of their death. The site is very busy and is subject to dropout with the sheer weight of traffic accessing the site, good resource though. The Information icon has details of the resource.

Yes the date they died in the services. Officially up to late 1921 or just into 1922 I think for ex service personnel which was still counted as a war casualty if attributable to injury during the war.